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Scantable Description
Introduction
The Scantable is the ASAP single-dish data container. It was designed based on the data abstraction of the PKSreader API.
Schema
The Scantable consist of a main (casacore) Table and several sub-tables which are referenced via _id_.
Main Table
The main table consists of global data (keywords) and row-based data (columns)
Columns
SPECTRA - Float(nchannel)
the spectral channel data.
FLAGTRA - uChar(nchannel)
the corresponding flags
TSYS - Float(nchannel)
the channel-based system temperature values
FLAGROW - uInt
spectrum based flags
TIME - MEpoch
The mjd time when the observation took place
INTERVAL - Double
the integration time in seconds
DIRECTION - MDirection
the associated direction on the sky
AZIMUTH, ELEVATION - Float
the azimuth/elevation when the spectrum was collected
SRCNAME - string
the name of the source observered
SRCTYPE - Int
the tyep of the source, i.e. indicating if it is an on source scan or off source. This will be used for calibration
SCANNO, BEAMNO, POLNO, IFNO, CYCLENO - uInt
These columns index (0-based) the respective values.
- SCANNO: the number odf the scan. A scan is usually multiple integrations
- (cycles)
- CYCLENO: the integration number within a scan (sub-scan?)
- IFNO: the index of the IF (spectral window)
- BEAMNO: the index of the beam (in a multibeam system)
- POLNO: the index of the polarisation, e.g. XX=0, YY=1, Real(XY)=2,
- Imag(XY)=3
REFBEAMNO - Int
optional index of the reference beam in a multibeam obervation
FREQ_ID, MOLECULE_ID, TCAL_ID, FOCUS_ID, WEATHER_ID, FIT_ID
Sub-Tables
FREQUENCY
blah blah
